The present invention relates to a cable lasher for use in lashing a cable, such as a telephone or transmission cable, to a support strand, such as a strand supported in the air between utility poles. More specifically, the present invention relates to a cable lasher that may be displaced along a support strand that is strung between utility poles so that a lashing wire is paid out during displacement of the cable lasher to helically wrap and securely tie the cable to the support strand.
Utility cables, such as telephone cables, are frequently routed between selected locations as overhead wiring suspended from a series of utility poles. In an effort to prevent the telephone cable from sagging between adjacent poles, the cables are frequently tied or lashed to a support strand that is tightly strung between the poles. For this purpose, a conventional lasher is pulled along the support strand with a tether either by a worker on the ground or with the assistance of a vehicle or capstan winch. The cable is first loosely supported by temporary support brackets hung from the support strand. The lasher is then mounted on the support strand in position to engage the loosely supported cable. As the lasher is pulled along the support strand, a lashing wire is helically wrapped around the transmission cable and the support strand in order to bind the cable to the tightly strung support strand.
One of the drawbacks, however, with conventional lashers is that a downward force must be exerted on the lasher by the tether to hold the lasher in proper contact with the support strand in order to properly drive the lashing mechanism to wrap the lashing wire around the cable and the support strand. Consequently, if the conventional lasher inverts during use, the lasher may become inoperative. Another problem is that any backward rotation of a conventional lasher during use causes the helically wrapped lashing wire to inadvertently slacken.
Another problem associated with conventional lashers is the inability to maintain uniform tension on the lashing wire during use. If uniform tension is not maintained, a uniformly tight wind cannot be achieved. In accordance with the present invention, a cable lasher is provided that overcomes many of the deficiencies in conventional lashers. The lasher of the present invention operates to effect a uniformly tight wind of lashing wire while preventing any slackening caused by inadvertent backward rotation of the lasher during use.
In accordance with the present invention, a cable lasher is provided for securing telephone and transmission cables to a support strand strung in the air between utility poles.
In general, the cable lasher is movable along the support strand so that the transmission cable is fed through the lasher. The lasher includes a support frame such as a central support tube that extends longitudinally through the lasher joining a front section to a rear section. A mid-section of the lasher is comprised of a rotating drum that is rotationally supported relative to the central support tube between the front and rear section of the lasher. The rotating drum may contain at least one reel of lashing wire for lashing the cable to the support strand. From the reel, the lashing wire is wrapped around tensioning rollers and then around a drive wheel to maintain constant tension in the lashing wire regardless of the amount of wire paid out during lashing. The free end of the lashing wire exits the rotating drum and is then tied off to provide the tension in the wire. As the lashing wire is reeled off during movement of the lasher along the support strand, the lashing wire drives the drive wheel which in turn drives a gearbox that translates linear movement of the lasher along the support strand into rotational movement of the drum. The gearbox causes the drum to rotate relative to the frame about the cable as the cable lasher rides on the support strand. As the drum rotates, wire from the reel of lashing wire is helically wrapped around the cable and the support strand lashing them together. The gearbox includes a drive wheel assembly that operates under the control of a one-way clutch provided on the drive wheel to control the rotational movement of the drum.
In specific operation, the cable lasher is moveably clamped onto the support strand in position so that the cable is operatively fed through a generally hollow interior of the lasher when the lasher is pulled from the ground with a handline by a worker or with the assistance of a vehicle or capstan winch. The cable lasher functions to maintain constant tension in the lashing wire through use of the tensioning rollers and the drive wheel so that a uniformly tight wind is effected. The tensioning rollers and the drive wheel are linked together by the lashing wire from the reel. The tensioning rollers cooperate with the drive wheel to maintain the constant tension in the wire as it is paid out from the reel of lashing wire during use.
The drive wheel assembly causes the drum to rotate as the lasher rides on the support strand. As the cable lasher moves along the support strand, the gearbox functions to translate linear motion of the lasher into rotational motion of the drum. For this purpose, the drive wheel is engageable, under control of a user-operated clutch, with a bevel gear of the gearbox to effect the translation of linear motion of the lasher into rotational motion of the drum. The bevel gear drives other gears of the gearbox to rotationally propel the drum. When in gear, the gearbox allows the rotating drum of the cable lasher to rotate as the lasher rides on the support strand. As the drum rotates, wire from the reel of lashing wire is helically wrapped around the cable and the support strand lashing them together. When the user-operated clutch is actuated to disengage the gearbox from the drive wheel, the drum is free to rotate in either rotational direction.
The drive wheel assembly operates during normal use to limit the rotational motion of the drum in a single rotational direction only. As the lasher rides along the strand, a one-way clutch provided on the drive wheel prevents the drive wheel from rotating in the opposite direction of the helical lashing. When the drive wheel is engaged with the gearbox, the one-way clutch of the drive wheel likewise prevents reverse rotation of the drum. If reverse rotation is needed, the user-operated clutch can be used to disengage the drive wheel from the bevel gear of the gearbox. For this purpose, the drive wheel has a hex head opening that accepts a mating hex head of the bevel gear to enable the bevel gear to be driven during rotation of the drive wheel. The hex head opening on the drive wheel can be disengaged from the mating hex head on the bevel gear by manual activation of the user-operated clutch. Manual displacement of a clutch release lever displaces a clutch fork which pushes the drive wheel out of engagement with the bevel gear. When the drive wheel is disengaged from the bevel gear, the gearbox is disengaged from the drive wheel and the rotating drum can be rotated in either direction. Additionally, the lashing wire can then be pulled from the lasher without motivating the gearbox to rotate the rotating drum.
The reel of lashing wire is recessed into the drum to prevent objects, such as existing cables from catching on the reel as the cable lasher rides along the support strand. A side door on the drum partially covers the recessed reel and is secured in a closed position with a lock bolt. The door as well as the exposed head of the lock bolt is also recessed within the outer circumference of the drum. Accordingly, objects are prevented from catching or snagging on the reel, the lock bolt, or the door as the cable lasher rides along the support strand.
An outer removable reel cover is provided on the reel to provide access to the supply of lashing wire on the reel. View slots may be provided in the outer reel cover so that the user can estimate the amount of wire remaining on the reel as the lashing wire is paid out. Since the side door only partially covers the reel, successive view slots become visible beneath the door even when the side door is closed. The use of wider view slots closer to the center of the reel is desirable to provide a better view as the reel gets closer to depletion.
A reel lock may be provided to hold the reel of lashing wire in stationary position on the drum as the removable reel cover is either removed or installed. For this purpose, the outside circumference of the reel of lashing wire has at least one lock notch. When the reel lock is moved into engagement with the lock notch, the reel of lashing wire is held stationary so that the reel cover may be installed and tightened into place.
A rear gate roller assembly is mounted on the rear end of the cable lasher providing a lower rear roller that may be swung opened and closed. The rear gate roller assembly includes a release knob for enabling the opening of the rear gate roller to permit the lasher to be placed on the cable. The rear gate roller cooperates with a pair of side rollers and an opposing upper rear strand roller to enclose and capture the cable therebetween. A thumb latch is located on the rear gate roller assembly to selectively permit adjustment of the position of the rear gate roller relative to the opposing strand roller along a shaft extending generally perpendicular between the gate roller and the strand roller. Movement of the gate roller up and down along the shaft enables the size of the opening for the cable between the rear gate roller and the opposing strand roller to be adjusted.
A series of rollers are also provided on the front end of the lasher to provide a circular roller surface generally conforming to the outer surface of the cable. The front rollers are configured with concave outer surfaces to engage the outer surface of the cable generally around the entire outer periphery of the cable so that the cable entering the cable lasher never contacts a static surface. The circular configuration of the rollers permits the cable to maintain constant contact with the concave surfaces of the rollers as the lasher rides on the support strand. A lower gate roller is provided which may be opened and closed to enable the cable to be inserted into the rollers. A front strand roller located on the front end of the lasher is provided in the series of rollers in position opposing the lower gate roller. The front strand roller is formed with a center groove for resting upon the support strand as the cable lasher rides on the support strand. The front strand roller includes a one-way clutch assembly to prevent reverse motion of the cable lasher. The front strand roller is also configured with a concave outer surface for engaging the cable so that the strand roller can simultaneously ride over both the support strand and the cable. The rear strand roller positioned at the rear end of the lasher may also include a strand groove for engaging the strand so that the rear strand roller simultaneously engages the support strand and the cable after being lashed together by the drum at the mid-section of the lasher.
A tapered front cowl is provided on the front end of the lasher to function as a nose cone to prevent objects from catching on the cable lasher as it rides along the support strand. The tapered front cowl covers the front end of the lasher and has a narrow front portion and a tail portion having an outer circumference that is larger than the recessed doors covering the mid-section drum. The tapered slope of the front cowl prevents objects from catching on the rotating drum as the cable lasher rides along the support strand.
Support strand locks are provided on the front end of the lasher to open and close a pair of movable front jaws that releasably grasp the support strand to retain the cable lasher on the support strand. The front jaws can be opened to receive the support strand and then closed into an overlapping position for holding onto the support strand. Support strand locks and jaws may also be located on the rear end of the lasher to provide additional safety as the cable lasher rides along the support strand.